Compositions of cupric salts and their use for the control of phytopathogentic fungi

ABSTRACT

A description follows of mixtures of copper (II) hydroxide with at least one other cupric salt having the formula (A) and their use for the control of phytopathogenic fungi. 
 
3Cu(OH) 2 .X(Y) n   (A)

The present invention relates to compositions based on cupric salts andtheir use for the control of phytopathogenic fungi.

In particular, the present invention relates to compositions based oncupric salts capable of effectively controlling phytopathogens whichcause damage to crops of economic interest.

Cupric hydroxide, cupric oxychloride (3Cu(OH)₂.CuCl₂), calcium cupricoxychloride (3Cu(OH)₂.CaCl₂), tribasic cupric sulfate (3Cu(OH)₂.CuSO₄),Bordeaux mixture (3Cu(OH)₂.CaSO₄), are active principles which are wellknown for being used singly in applications on the leaves for thecontrol of phytopathogens. These cupric active principles are described,for example in “THE PESTICIDE MANUAL, 12th EDITION, BRITISH CROPPROTECTION COUNCIL, Pages 200-205”.

It is known and recognized that cupric hydroxide is more effective withrespect to other cupric species, which allows it to be used at lowerdoses. At the same time, however, cupric hydroxide has a greaterphytotoxicity.

The applicant has now found that mixtures of copper (II) hydroxideallows the drawbacks of the known art to be overcome.

An object of the present invention therefore relates to mixtures ofcopper(II) hydroxide with at least one other cupric salt having formula(A):3Cu(OH)₂.X(Y)_(n)  (A)wherein:

-   -   X represents the copper(II) or calcium (II) ion;    -   Y has the meaning of a chloride or sulfate ion;    -   n is an integer which can have the value of 1 or 2.

A further object of the present invention relates to the use of mixturesof copper(II) hydroxide with at least one other cupric salt havingformula (A)3Cu(OH)₂.X(Y)_(n)  (A)wherein:

-   -   X represents the copper(II) or calcium (II) ion;    -   Y has the meaning of a chloride or sulfate ion;    -   n is an integer which can have the value of 1 or 2.        for the control of phytopathogenic fungi in agricultural crops.

An object of the present invention preferably relates to mixtures ofcopper(II) hydroxide with cupric oxychloride (3Cu(OH)₂.CuCl₂), orcalcium cupric oxychloride (3Cu(OH)₂.CaCl₂), or tribasic cupric sulfate(3Cu(OH)₂.CuSO₄), or Bordeaux mixture (3Cu(OH)₂.CaSO₄), and their usefor the control of phytopathogens.

Mixtures of copper(II) hydroxide with at least one other cupric salt,such as cupric oxychloride (3Cu(OH)₂.CuCl₂), calcium cupric oxychloride(3Cu(OH)₂.CaCl₂), tribasic cupric sulfate (3Cu(OH)₂.CuSO₄), Bordeauxmixture (3Cu(OH)₂.CaSO₄), do, in fact, have an unexpected synergisticaction which allows the control of many phytopathogenic agents, at thesame time enabling lower doses of metallic copper to be used, withrespect to those normally adopted for the single components.

The compositions, object of the present invention, are consequentlycapable of effectively controlling numerous phytopathogens which causeconsiderable damage to crops of economic interest.

Examples of phytopathogenic fungi which can be effectively controlledwith the compositions of the invention are Plasmopara viticola,Phytophthora infestans, Bremia lactucae, Venturia inaequalis.

The mixtures, object of the present invention, can be obtained bymechanically mixing suitable quantities of copper(II) hydroxide and oneor more cupric salts having formula A as defined above, or by mixingsingle salts already formulated in the form of specific compositions.

Alternatively, the mixtures, object of the present invention, can alsobe prepared by the partial transformation of a suspension of cupricsalts having formula A selected from cupric chloride, cupric sulfate orcupric oxychloride, with an alkaline hydroxide, such as sodium orpotassium or calcium hydroxide. The conditions of these reactions can beextracted, for example, from International Publication No. WO 02/083566,suitably reducing the prescribed quantities of alkaline hydroxide.

The weight ratio between copper(II) hydroxide and the cupric salt havingformula (A) in the above mixtures, can vary from 1:20 to 20:1,preferably from 1:10 to 10:1, in particular from 1:2 to 2:1.

These mixtures can be used in agronomic practice for applications onplants or a part thereof, in particular on all parts of the plant, onthe leaves, stems, branches and roots, or on the earth in which theplant grows.

The mixtures, object of the present invention, can be conveniently usedin agronomic practice alone or combined with other active principles(fungicides).

An object of the present invention therefore also relates to the use ofsaid mixtures in a combination with one or more other active principlesboth as specifically prepared compositions or as an extemporaneousblending of the single components.

As an illustrative but non-limiting example, some active principleswhich can be conveniently used in a mixture with the compounds, objectof the present invention, are listed below:

-   cymoxanil, fosetyl, benalaxyl, benalaxyl-M (R isomer of benalaxyl),    metalaxyl, oxadixyl, ofurace, mancozeb, maneb, zineb, fenamidone,    famoxadone, procymidone, chlozolinate, vinclozolina, iprovalicarb,    dimethomorph, propamocarb, prothiocarb, hymenaxol, pencicuron,    etridiazole, analogous synthetic products of strobilurines (such as    azoxystrobin, kresoxim methyl), captane, folpet, dinocap, sulfur,    thiram, tolclofos methyl, chlorothalonil, azoles inhibitors of the    biosynthesis of ergosterol (such as tetraconazole myclobutanyl,    hexaconazole, epoxy-conazole), micro-organisms (such as Ampelomyces    quisqualis), BAS512, IKF916, IR5885, ethaboxam, zoxamide, fluazinam.

In order to be conveniently used in agriculture, the mixtures, object ofthe present invention, and also combinations of said mixtures with oneor more other active principles, can also be suitably formulated inorder to favour the distribution and adhesion to the vegetable to beprotected.

Compositions in the form of wettable powders, concentrated suspensions,granulates, etc., can be used.

The compositions are prepared with known methods, for example bydiluting the active substances with liquid or solid mediums, optionallyin the presence of surface-active agents.

Liquid diluents which can be used are, for example: water, aromatic orparaffinic organic solvents, alcohols, esters, ketones, amides.

Solid diluents, or also carriers, which can be used are, for example:silica, kaolin, bentonite, talc, infusorial earth, dolomite, calciumcarbonate, magnesia, chalk, clays, synthetic silicates, attapulgite,seppiolite.

Surface-active agents which can be used are, for example: salts ofsodium, potassium, triethanolamine of: alkyl naphthalene sulfonates,condensed alkyl naphthalene sulfonates, phenyl sulfonates,polycarboxylates, sulfosuccinates, alkyl sulfo-succinates, alkylsulfates, lignin sulfonates, polyethoxylated fatty alcohols, alkylarylsulfonates, polyethoxylated alkyl phenols, polyethoxylated esters ofsorbitol, polypropoxy polyethoxylates (block polymers).

The compositions can also contain special additives for particularpurposes, such as, for example antifreeze agents: propylene glycol, oradhesion agents such as Arabic rubber, polyvinyl alcohol, polyvinylpyrrolidone, etc.

In the formulations, the percentage content of the mixtures, object ofthe present invention, can vary from 1% to 95%, preferably from 5% to70%.

The following examples are exclusively provided for illustrativepurposes and do not limit the scope of the present invention.

EXAMPLE 1

Preparation of a Wettable Powder.

A formulation of the wettable powder type at 50% of copper (WP 50) wasprepared by suitably mixing and grinding the following ingredients:INGREDIENTS QUANTITY % (w/w) Technical cupric hydroxide at 93.7% 41.0 (Cu content = 61%) (equal to 25% of Cu) Technical cupric oxychloride at96.6% 43.5  (Cu content = 57.5%) (equal to 25% of Cu) Alkyl sodiumnaphthalenesulfonate 1.5 Sodium polycarboxylate 1.0 Sodium ligninsulfonate 3.0 Silica 1.0 Calcium carbonate 9.0

EXAMPLE 2

Preparation of a Concentrated Suspension

A formulation of the concentrated suspension type at 20% of copper(SC20) was prepared by suitably mixing and grinding the followingingredients: INGREDIENTS QUANTITY % (w/w) Technical cupric hydroxide at93.7% 16.4  (Cu content = 61%) (equal to 10% of Cu) Technical cupricoxychloride at 96.6% 17.4  (Cu content = 57.5%) (equal to 10% of Cu)Polyethoxylated fatty alcohol 2.5 Polyethoxylated alkylaryl phenol, 2.5Triethanol amine salt Polysaccharide 0.3 Propylene glycol 4.0Preservative 0.4 Anti-foam agent 0.1 Water 56.7 

EXAMPLE 3

Preparation of Dispersible Granules

A formulation of the dispersible granule type at 50% of copper (WG 50)in water, was prepared by suitably mixing, grinding and granulating thefollowing ingredients: INGREDIENTS QUANTITY % (w/w) Technical cuprichydroxide at 93.7% 41.0  (Cu content = 61%) (equal to 25% of Cu)Technical cupric oxychloride at 96.6% 43.5  (Cu content = 57.5%) (equalto 25% of Cu) Alkyl sodium naphthalene sulfonate 1.0 Sodiumpolycarboxylate 2.0 Sodium lignin sulfonate 8.0 Kaolin 4.5

EXAMPLE 4

Determination of the Biological Efficacy in Greenhouse.

Using the composition described in Example 1, a greenhouse test wascarried out, for the control of Phytophthora infestans (tomato mildew)compared with commercial formulation of cupric hydroxide and cupricoxychloride used singly. A random block experimental scheme was used,which included 3 replications and 10 plants for each lot. An artificialinoculation of the pathogen was effected 24 h after the treatment withthe product.

The degree of action of the products was recorded after 7 days.

The synergistic effect of the mixture was evaluated by comparing theexperimental data obtained with the theoretical efficacy valuecalculated according to the Limpel formula (“Pesticide Science” (1987),vol. 19, pages 309-315:E=x+y−xy/100wherein:

E is the expected fungicidal activity from a mixture obtained by mixingg·x of the compound X with g·y of the compound Y;

-   -   x is the activity of the compound X when used alone at a dose of        g·x;    -   y is the activity of the compound Y when used alone at a dose of        g·y.

An experimental fungicidal activity higher than the calculated value ofE, should be considered as being a synergistic effect.

The data obtained are indicated in Table 1. TABLE 1 ApplicationCorresponding Expected dose of cupric dose efficacy Observed Observedefficacy/ Formulation formulate (g/hl) (g/hl) (Limpel) efficacy expectedefficacy Cupric hydroxide 100 40 — 38 (WP 40%) Cupric oxychloride 80 40— 31 (WP 50%) Cupric hydroxide + 160 80 57.2 80 1.40 Cupric oxychloride(50% WP)

EXAMPLE 5

Determination of the Biological Efficacy in the Field.

A field efficacy test was carried out, using the composition describedin Example 1, for the control of Plasmopara viticola (vine mildew)compared with commercial formulations of cupric hydroxide and cupricoxychloride used singly. A random block experimental scheme was usedwhich included 4 replications and 15 plants for each parcel. Calendartreatments were effected (7-8 days) and the degree of action of theproducts was registered 12 days after the fifth and last treatment,compared with the non-treated blank; the synergistic effect of themixture was evaluated on the basis of the expected efficacy according toLimpel.

The data obtained are indicated in Table 2. TABLE 2 CorrespondingEfficacy observed/ Application dose cupric dose Expected efficacyObserved efficacy Formulation of formulate (g/hl) (g/hl) (Limpel)Efficacy expected Cupric hydroxide 100 40 — 35 (WP 40%) Cupricoxychloride 80 40 — 30 (WP 50%) Cupric hydroxide + 160 80 54.5 75 1.37Cupric oxychloride (50% WP)

1. Mixtures of copper (II) hydroxide with at least one other cupric salthaving formula (A):3Cu(OH)₂.X(Y)_(n)  (A) wherein: X represents the copper (II) or calcium(II) ion; Y has the meaning of a chloride or sulfate ion; n is aninteger which can have the value of 1 or 2:
 2. The mixtures according toclaim 1, characterized in that they comprise copper (II) hydroxide withat least one other cupric salt selected from cupric oxychloride(3Cu(OH)₂.CuCl₂), calcium cupric oxychloride (3Cu(OH)₂.CaCl₂), tribasiccupric sulfate (3Cu(OH)₂.CuSO₄), Bordeaux mixture (3Cu(OH)₂.CaSO₄). 3.The mixtures according to claim 1, characterized in that the weightratio between copper(II) hydroxide and the cupric salt having formula(A) ranges from 1:20 to 20:1.
 4. The mixtures according to claim 1,characterized in that the weight ratio between copper(II) hydroxide andthe cupric salt having formula (A) ranges from 1:10 to 10:1.
 5. Themixtures according to claim 1, characterized in that the weight ratiobetween copper(II) hydroxide and the cupric salt having formula (A)ranges from 1:2 to 2:1.
 6. A process for the preparation of mixturesaccording to the claim 1, characterized in that it comprises amechanical blending of copper(II) hydroxide and one or more cupric saltshaving formula A as defined above, or by mixing the single salts alreadyformulated in the form of specific compositions.
 7. The process for thepreparation of mixtures according to one of the claim 1, characterizedin that it comprises a partial transformation of a suspension of cupricsalts having formula A selected from cupric chloride, cupric sulfate orcupric oxychloride, with an alkaline hydroxide, such as sodium orpotassium or calcium hydroxide.
 8. Use of mixtures of copper(II)hydroxide with at least one other cupric salt having formula (A):3Cu(OH)₂.X(Y)_(n)  (A) wherein: X represents the copper(II) or calcium(II) ion; Y has the meaning of a chloride or sulfate ion; n is aninteger which can have the value of 1 or
 2. for the control ofphytopathogenic fungi.
 9. The use according to claim 8, of mixturescomprising copper (II) hydroxide with at least one other cupric saltselected from cupric oxychloride (3Cu(OH)₂.CuCl₂), calcium cupricoxychloride (3Cu(OH)₂.CaCl₂), tribasic cupric sulfate (3Cu(OH)₂.CuSO₄),Bordeaux mixture (3Cu(OH)₂.CaSO₄).
 10. The use according to claim 8,wherein the phytopathogenic fungi are Plasmopara viticola, Phytophthorainfestans, Bremia lactucae, Venturia inaequalis.
 11. A method forcontrolling phytopathogenic fungi in agricultural crops by theapplication of the mixtures according to claim
 1. 12. The methodaccording to claim 11, characterized in that the application is effectedon all parts of the plant, on the leaves, stems, branches and roots, oron the earth in which the plant grows.
 13. Fungicidal compositionscontaining a mixture according to claim 1 together with other activeprinciples, such as other fungicides.
 14. The compositions according toclaim 13, characterized in that the other fungicides are selected from:cymoxanil, fosetyl, benalaxyl, benalaxyl-M (R isomer of benalaxyl),metalaxyl, oxadixyl, ofurace, mancozeb, maneb, zineb, fenamidone,famoxadone, procymidone, chlozolinate, vinclozolina, iprovalicarb,dimethomorph, propamocarb, prothiocarb, hymenaxol, pencicuron,etridiazole, analogous synthetic products of strobilurine (such asazoxystrobin, kresoxim methyl), captane, folpet, dinocap, sulfur,thiram, tolclofos methyl, chlorothalonil, azoles inhibitors of thebiosynthesis of ergosterol (such as tetraconazole myclobutanyl,hexaconazole, epoxyconazole), micro-organisms (such as Ampelomycesquisqualis), BAS512, IKF916, IR5885, ethaboxam, zoxamide, fluazinam. 15.The compositions according to claim 13, characterized in that thepercentage content of the mixture based on cupric salts varies from 1%to 95%.
 16. The compositions according to claim 15, characterized inthat the percentage content of the mixture based on cupric salts variesfrom 5% to 70%.